Chillingo announced early Monday that they will be extending their one-time discount of Guerilla Bob for the iPhone and iPod touch until this coming Wednesday, February 24, 2010.

As part of the launch marketing push, Chillingo took 50 percent off the game’s retail price, allowing you to pick it up over the next 48 hours for just 99 cents. The sale celebrates the impending update that will take the mayhem of Guerrilla Bob to the next level, Chillingo said.

A series of new features that will spice up the Guerilla Bob experience include the new Mercenary game mode, in addition to a new array of upgradeable hardcore weapons.

“It’s going to be really great,” Chillingo’s head of US marketing Marta Miernik told me in an email interview. An in-game shop where you’ll be able to pick up and upgrade the following weapons is also in the works: Baseball bat, bomb pack, Molotov cocktail, chainsaw, machinegun, shotgun, rocket launcher, grenade launcher, flamethrower, double uzis, sticky bow, and chaingun.

Developed by the team called Angry Mob Games, Guerilla Bob files as a John Rambo-styled shooter with lots of eye candy and plenty of weaponry, in which the terrorists are the bad guys. Your character in the current Guerilla Bob version can carry three upgradeable weapons and switch between them any time: The machine gun for spraying your enemies, rocket launcher to spread damage, and flamethrower that’s especially handy in close encounters.

The 1.0 version of the game debuted a month ago as a $2.99 download. The game has been updated to version 1.1 last week, adding sought-after game saving functionality with multiple save slots. Previously, you’d have to start over when you die. The new version also added score multiplier and an improved scoring system, as well as improved sound effects and updated support for Chillingo’s social gaming network dubbed Crystal.

Guerrilla Bob for iPhone (sale)

Guerrilla Bob for iPhone (weapon shop)

Guerrilla Bob for iPhone (screenshot 001)

Guerrilla Bob for iPhone (screenshot 002)

Guerrilla Bob for iPhone (screenshot 003)

Guerrilla Bob for iPhone (screenshot 004)

The next version is still a month and a half from being finished so now could be the right time to grab yourself a discounted copy of Guerilla Bob, especially if you like blowing stuff up. We will be reviewing Guerilla Bob shortly.